PROJECT SUMMARY This proposal aims to answer a simple question: how do we feel? The transduction of physical forces into cellular biochemical signals (mechanosensation) is central to a remarkable breadth of biological processes. This includes the familiar senses of touch, hearing, balance and pain as well as myriad subconscious force sensations involved in blood pressure regulation, osmolality control, proprioception, organ function, and cellular growth and development. Dysregulation of mechanosensation is associated with disease and pathophysiology including deafness, atherosclerosis, chronic pain and cancer. Remarkably, mechanosensation is still poorly understood and an integrated description of where and how forces are sensed by cells remains elusive. The objective of this proposal is to develop new approaches for studying forces and force sensors to enable the discovery of physical, molecular and cellular principles of mechanosensation in its many physiological contexts. Novel platforms are proposed for creating (i) reporters of specific forces which will be used to understand the spatial and temporal distribution of forces a cell experiences, (ii) labeling reagents and activity probes for specific mechanosensors to reveal their cellular localizations and activities and (iii) pharmacological modulators of mechanosensors to define their roles in determining a cell's response to force. In addition to enabling the study of fundamental aspects of mechanosensation, these tools will also provide a means to evaluate the potential of targeting specific mechanosensors to improve human health and treat disease. Crucially, these approaches and tools will be widely applicable and will provide insights across the broad scope of biology in which physical forces and force sensors play important roles.